#判断一个数是否是正整数
a = 88
if a >= 0:
	print("yes");
else:
	print("no");
	pass

#字符串
b = "niha \\ buhao \n我是下一行";
print(b);

c = r"\\ -- \n -- \t";
print(c);

e = "我是字符串";
print(e);
e = 888;
print(e);

f = 'bian liang ce shi';
g = f;
f = '9999';
#g = f;
print(g);